自动管电流调制技术在腹部CT检查中的应用研究

发布时间：2018-05-22 07:35

本文选题：Pubmed + CNKI　；参考：《北京协和医学院》2013年硕士论文

【摘要】：目的：探讨近十年来国内外CT低剂量领域的研究现状,揭示该领域的发展特点和规律,为该领域的进一步研究提供参考。材料及方法：以PubMed为搜索引擎的Medline数据库,中国知网(CNKI)的中国学术期刊网络出版总库(China Academic Journal Network Publishing Database,CAJD)以及Web of Science的科学引文数据库(Science Citation Index, SCI)中2002年—2011年间国内外发表的CT低剂量研究论文为研究对象,采用Thomson Data Analyzer (TDA)分析软件进行数据清洗,从作者合作趋势、机构、机构合作度、期刊发文趋势、国家和国内地区分布、高被引文献、热点词频等方面进行文献计量学,并利用SAS8.2编程做聚类分析。结果：2002年—2011年间Medline共收录CT低剂量文献6433篇；CNKI收录3148篇；Web of Science收录6027篇。此领域的高产作家为发表文献4篇以上的作家。CT低剂量领域相关的9种核心期刊在国际放射学领域拥有较高影响因子。其中,Medical Physics、European Journal of Radiology和American Journal of Roentgenology成为该领域发表高质量论文最具代表性的期刊,且发文量保持逐年快速增长。单篇论文平均作者数5.93,合作率为89.4%,单篇论文平均机构数2.63,合作率为77.3%,并均呈现逐年递增趋势。按国家划分,美国发文量3165篇,占总文献量的49.2%,成为CT低剂量研究的核心力量区。而我国十年来在该领域发表SCI论文共计174篇,发文量较少。我国CT低剂量研究发文作者来自471个相关机构、33个主要地区,其中北京、上海两地总发文量占45.9%。该领域涉及10种核心期刊,其中以中国医学影像技术、中华放射学杂志发文量最高。该领域十年间获基金资助发文量868篇,占国内总发文量的27.57%。CT低剂量的研究热点主要涉及肺癌筛查、冠状动脉造影检查、肺动脉栓塞检查、CT结肠仿真内窥镜技术、CT辐射剂量等。结论：十年间CT低剂量研究在国内外都得到了大量开展并得到了行业的广泛关注。CT低剂量研究己初具规模。CT低剂量研究是涉及医学、工学、数理学等多学科的交叉科学,多作者、多学科、多机构间的广泛合作有助于开展更为深入的研究。我国CT低剂量研究与国际同期水平相比尚处于初级阶段,科研力量地区分布极不均衡。相关研究的发文数量、质量还有待于进一步提高。加强CT低剂量相关的基础研究以及相关研究的创新性,完善CT低剂量研究所涉及的医学伦理、临床科研方法等不足可加快该领域研究不断深入的步伐。目的：探讨个体化因素对成人腹部CT图像质量的影响,筛选最具代表性且简单易行的指标作为调节成人腹部CT扫描参数的分组标准。并确定成人腹部CT图像质量客观测量的最佳层面区域。材料及方法：对2012年3月-10月间有临床诊断或治疗需求的144例患者,以固定管电流模式行腹部CT平扫检查。记录患者的身高、体重,并测量定位像上经L1椎弓根水平的腹左右径,测量腹部CT横断面图像经第一肝门水平的腹部径向数据。利用3D reformat软件的X SECTION功能在脐水平测量腹腔内脂肪含量百分比及皮下脂肪厚度数据。考察这些个体化因素与腹部CT图像质量间的相关性。选择腹部常规CT检查图像的肝顶、第一肝门、肾门、肾下极4个层面的腹主动脉区以及第一肝门层面出现的其他代表性的6个测量区(门静脉、肝实质周边、肝实质中心、脾、竖脊肌、前腹壁皮下脂肪)进行图像噪声测量。比较在相关性较高的个体化参数作为基础水平下所有测量区的噪声值与图像质量间的相关性,从而最终确定成人腹部常规CT检查图像的客观评价测量的最佳区域。结果：各种个体化因素与客观图像质量噪声值间的相关系数分别是0.267(身高)、0.702(体重)、0.7(体重身高比)、BMI(0.661)、0.744(定位像L1椎弓根水平腹左右径测量值)、0.739(最大腹横径)、0.712(最大腹前后径)、0.765(上腹部平均最大径)、0.613(内脏脂肪测量值)、0.431(皮下脂肪测量值)。且定位像上腹左右径测量值与第一肝门水平最大腹横径测量值间比较,有强相关(R=0.931)。以腹平均径为基础水平,4个层面腹主动脉区测量的噪声值与图像质量的相关性系数R为0.522-0.765,第一肝门层面相关性最高。以相关性较高的个体化因素为不同的基础水平,第一肝门层面的肝实质周边测量区的噪声值与图像质量相关性最高(R0.74-0.802),腹主动脉次之(R0.712-0.765)。前腹壁皮下脂肪与图像质量的相关性最差(R=0.412,P0.05)。结论：本研究涉及的个体化因素与图像质量间有相关性(0.267-0.765),其中腹部径向因素的相关性最高。定位像L1椎弓根水平腹左右径测量值可作为简便易行的调节成人腹部CT扫描参数的指标。第一肝门层面的腹主动脉区是成人腹部常规CT检查图像质量客观评价测量的最佳区域,其噪声测量值在一定程度上可指标腹部常规CT扫描的客观图像质量。目的：探讨自动管电流调制技术对成人腹部CT扫描的图像质量及辐射剂量影响。材料及方法：(1)模体研究：选用Catphan600性能测试模型为观察对象,配合成人腹部体环模拟成人腹部CT低、高对比特点。采用常规腹部标准电压120kv,固定管电流450mA及自动毫安技术NI值设置为4-14、16、18、20,管电流范围10-450mA对模型进行扫描。测量catphan600均质区域CT值,验证模型对X线衰减的等效性。记录每组扫描方案的辐射剂量指标容积CT剂量指数(CTDIvol)、个体化剂量估计值(SSDE)、剂量长度积(DLP)、有效剂量(ED)：图像质量客观评价指标图像噪声值(SD)、对比-噪声比(CNR)。同时由3名来自3家医院分别有5年以上工作经验的腹部诊断医师对catphan600中的低对比可探测能力(low contrast detectability, LCD)及高对比可探测能力(high contrast detectability, HCD)进行独立观察和评分。分析不同NI值与图像质量主、客观评价指标及辐射剂量指标间的相关性,并比较不同NI值与腹部标准扫描条件下所得到的SD、CNR及HCD.LCD评分间的差异。(2)选取2012.3至2013.3间需腹部CT平扫患者120例,按比例分层分配随机抽样方法以定位像上经L1水平测量腹横径(D/cm)不同为区组标准,分为实验组及对照组共6组,每组20例。实验组以120kv, ATCM (NI=10),管电流范围10-450mA;对照组120kv、450mA完成扫描。测量肝顶、肝门、肾下极3个层面的腹主动脉区图像噪声值。由3名医师独立进行腹主动脉、门静脉、肝脏、脾脏、胰腺、肾脏6个器官的主观噪声评价和肝门、胰腺、肾门3个层面的图像可接受率评价。记录并计算受检者所受辐射剂量指标及主要层面的毫安值。图像质量评分比较采用秩和检验,各区组间图像噪声值及辐射剂量指标采用方差分析,各区组内两两比较采用t检验。结果：(1)此模型与成人腹部对X线衰减具有较好的等效性。NI值与图像质量主、客观评价指标及辐射剂量指标间呈较高的线性相关(r=0.758-0.965,P0.01)；实验组NI=4-7组与对照组间SD、CNR差异均无统计学意义(t值分别为一0.17-1.63,0.03～1.12,P值均0.05)。实验组NI=4-10组与对照组间LCD评分差异均无统计学意义(Z值为一0.313～1.637,P值均0.05)。实验组NI=4～13组与对照组间HCD得分差异均无统计学意义(Z值为一0.147-一1.423,P值均0.05)。(2)实验组及对照组的主观图像质量评分比较差异无统计学意义(Z=-1.831--1.000,P值均0.05)：实验组与对照组在D-≤33.4cm区组辐射剂量指标比较差异有统计学意义(t=-6.13--3.93,P值均0.05)；实验组内各区组及各层面间图像噪声测量值比较差异无统计学意义(F=0.46-1.37,P值均0.05)；实验组各区组间辐射剂量指标比较差异有统计学意义(F=15.88-42.78,P值均0.05)。结论：当NI值在8-10时,在保证图像质量LCD评分指标不受影响的前提下,与腹部标准扫描条件相比降低25.33%的辐射剂量。随NI值的改变HCD的变化不大,当NI≥14时HCD显著下降。在腹部CT扫描中应用ATCM(NI=10)技术可保证低对比病灶检出能力不受影响,与此同时使辐射剂量与固定管电流模式相比下降11.2%-78.3%。
[Abstract]:Objective: To explore the research status of CT low dose field at home and abroad in recent ten years, and to reveal the characteristics and laws of the development in this field, and to provide reference for further research in this field.
Materials and methods: the Medline database of PubMed as the search engine, the China Academic Journal Network Publishing Database, CAJD, and the scientific citation database from 2002 to 2011 of the Chinese Academic Journal (CNKI). The quantity research paper is the research object, using the Thomson Data Analyzer (TDA) analysis software to carry on the data cleaning, from the author's cooperation trend, the organization, the organization cooperation degree, the periodical issuing trend, the national and domestic distribution, the high cited literature, the hot word frequency and so on, and using SAS8.2 programming to do cluster analysis.
Results: from 2002 to 2011, Medline included 6433 low doses of CT, 3148 CNKI and 6027 of Science. The high-yield writers in this field have higher influence factors in the field of international Radiology, which have more than 4 writers in the field of low dose.CT. Among them, Medical Physics, Europe An Journal of Radiology and American Journal of Roentgenology have become the most representative periodicals of high quality papers published in this field, and the amount of writing is increasing rapidly year by year. The average author number of single paper is 5.93, the rate of cooperation is 89.4%, the average number of single papers is 2.63, the cooperation rate is 77.3%, and the trend of increasing year by year is increasing. According to the country, the number of papers is increasing year by year. In the United States, 3165 articles, accounting for 49.2% of the total amount of literature, have become the core strength area of CT low dose research. In our country, there are 174 papers published in this field in the past ten years in this field, and the amount of writing is less. The author of low dose research in CT of our country comes from 471 related institutions and 33 main areas, including Beijing and Shanghai, which account for 45.9%. The field involves 10 core periodicals, among which Chinese medical imaging technology, the Chinese Journal of radiology has the highest amount of delivery, and 868 of the funds have been funded in the field in ten years, and the low dose of 27.57%.CT, which accounts for the total amount of domestic service, is mainly involved in lung cancer screening, coronary angiography, pulmonary embolism, and CT colon simulation. Mirror technology, CT radiation dose and so on.
Conclusion: the low dose study of CT in the past ten years has been carried out in a large amount both at home and abroad and received extensive attention from the industry..CT low dose research has begun to take initial scale,.CT low dose research is a cross science involving medicine, engineering, mathematics and other disciplines. Many authors, multidisciplinary and multi agency cooperation will help to carry out more in-depth research. The low dose study of CT in China is still in the primary stage compared with the international level of the same period. The distribution of scientific research forces is very uneven. The quantity and quality of the related research are still to be further improved. The basic research on the low dose of CT and the innovation of related research are strengthened, and the medical ethics involved in the low dose research of CT is perfected, and the clinical department is perfected. Deficiencies in research methods can speed up the pace of research in this field.
Objective: To investigate the influence of individualized factors on the quality of adult abdominal CT images, and to screen the most representative and simple index as a standard for adjusting the CT scan parameters of adult abdomen, and to determine the optimal level area for the objective measurement of the quality of CT images in the abdomen of adults.
Materials and methods: 144 patients with clinical diagnostic or therapeutic needs during the -10 month of March 2012 were performed abdominal CT scan with fixed tube current mode. The height and weight of the patients were recorded and the abdominal diameter of the pedicle of the L1 pedicle on the positioning image was measured, and the abdominal radial data of the abdominal CT cross section like the level of the first hepatic portal was measured. The X SECTION function of the 3D reformat software was used to measure the percentage of intraperitoneal fat content and the thickness of subcutaneous fat at the umbilical level. The correlation between these individualized factors and the mass of the abdominal CT image was examined. The liver top, the first hepatic portal, the renal gate, the 4 layers of the subrenal pole, and the first hepatic hilar layer were selected for the abdominal routine CT examination. Image noise measurement of 6 other representative areas (portal vein, liver parenchyma, liver parenchyma center, spleen, erect ridge muscle, subcutaneous fat in the anterior abdominal wall). The correlation between the noise value of all measured areas and the quality of image in all measured areas was compared, and the adult abdomen was finally determined. The best area of measurement is objective evaluation by routine CT examination.
Results: the correlation coefficients between the individual factors and the objective image quality noise values were 0.267 (height), 0.702 (weight), 0.7 (weight to height ratio), BMI (0.661), 0.744 (the location of the L1 pedicle horizontal abdominal diameter measurement), 0.739 (the largest abdominal transverse diameter), 0.712 (the maximum abdominal diameter), 0.765 (the average maximum diameter of the upper abdomen), 0.613 (visceral fat). The measurement value of the fat), 0.431 (subcutaneous fat measurement). There is a strong correlation between the measured values of the upper abdominal diameter and the maximum abdominal transverse diameter of the first hepatic portal (R=0.931). It is based on the average diameter of the abdomen, and the correlation coefficient of the noise value measured by the abdominal aorta at the 4 levels and the image quality is 0.522-0.765, the first liver gate level. The correlation was the highest. With the higher correlation of individualized factors as the basic level, the correlation between the noise value of the parenchyma surrounding area at the first hepatic portal level and the image quality was the highest (R0.74-0.802), the abdominal aorta was (R0.712-0.765). The correlation between the subcutaneous fat of the anterior abdominal wall and the image quality was the worst (R=0.412, P0.05).
Conclusion: there is a correlation between the individual factors and the image quality involved in this study (0.267-0.765), and the correlation between the abdominal radial factors is the highest. The measurement value of the horizontal abdominal diameter of the pedicle of the pedicle of the L1 can be used as an easy and easy parameter to regulate the CT scanning parameters of the adult abdomen. The abdominal aorta of the first hepatic portal is the routine of the abdominal routine. CT image quality is the objective area to evaluate the best area of measurement, and its noise measurement value can indicate the objective image quality of abdominal routine CT scan to a certain extent.
Objective: To investigate the effect of automatic tube current modulation on image quality and radiation dose of adult abdominal CT scan.
Materials and methods: (1) model body study: using the Catphan600 performance test model as the observation object, combined with adult abdominal body ring to simulate adult abdominal CT low and high contrast characteristics. The conventional abdominal standard voltage 120kv, the fixed tube current 450mA and the automatic Ma technique NI value are set to 4-14,16,18,20, and the tube current range 10-450mA is used to scan the model. The CT value of the catphan600 homogeneous region was measured to verify the equivalence of the model for X-ray attenuation. The dose index volume CT dose index (CTDIvol), individual dose estimate (SSDE), dose length product (DLP), effective dose (ED), image quality objective evaluation index image noise value (SD), contrast noise ratio (CNR), were recorded in each group. 3 abdominal diagnostics with more than 5 years' experience from 3 hospitals were independently observed and graded on the low contrast detectability (low contrast detectability, LCD) and high contrast detectability (high contrast detectability, HCD) in catphan600. The correlation between the dose of radiation dose and the difference between the different NI values and the SD, CNR and HCD.LCD scores under the abdominal standard scan. (2) 120 cases with abdominal CT scan were selected from 2012.3 to 2013.3, and the proportional stratified distribution random sampling method was used to locate the L1 level of the abdominal transverse diameter (D/cm) as the regional group standard. The experimental group and the control group were 6 groups, with 20 cases in each group. The experimental group was 120kv, ATCM (NI=10), the tube current range 10-450mA, the control group 120kv, 450mA completed the scanning. The image noise values of the abdominal aorta in 3 levels of the liver top, the hepatic portal and the lower renal pole were measured. The main 6 organs of the abdominal aorta, the portal vein, the liver, the spleen, the pancreas, and the kidneys were operated by 3 physicians. The evaluation of the image acceptance rate and the evaluation of the image acceptability of the 3 levels of the liver gate, the pancreas and the portal, recorded and calculated the doses of radiation dose and the values of the main level. The image quality score was compared with the rank sum test. The image noise value and the radiation dose index were analyzed by the variance, and the t test was used in the 22 areas in each group.
Results: (1) this model has a good equivalent.NI value with the image quality of the X-ray attenuation in the adult abdomen, and a higher linear correlation between the objective evaluation index and the radiation dose index (r=0.758-0.965, P0.01); the difference of SD and CNR between the NI=4-7 group and the control group in the experimental group is not statistically significant (t value is 0.17-1.63,0.03 to 1.12, P value, respectively. All 0.05). There was no significant difference in LCD score between the experimental group NI=4-10 and the control group (Z value was 0.313 to 1.637, P value was 0.05). There was no statistical difference between the experimental group NI=4 and 13 groups and the control group (Z value was one 0.147- 1.423, P value 0.05). (2) the subjective image quality score of the experimental group and the control group was different. The significance of the study (Z=-1.831--1.000, P value are 0.05): the comparison of the radiation dose indices between the experimental group and the control group in the D- < 33.4cm area group was statistically significant (t=-6.13--3.93, P value was 0.05); there was no statistical significance (F=0.46-1.37, P value 0.05) in the experimental group and the various levels of the experimental group (F=0.46-1.37, P value, 0.05). The difference of radiation dose index was statistically significant (F=15.88-42.78, P = 0.05).
Conclusion: when the NI value is 8-10, the radiation dose is reduced by 25.33% on the premise of ensuring the image quality LCD score is not affected. With the change of NI value, the change of HCD is not significant, and when NI is more than 14, HCD decreases significantly. The application of ATCM (NI=10) technique in the abdominal CT scan can guarantee the low contrast detection ability. At the same time, the radiation dose is reduced by 11.2%-78.3%. compared with the fixed tube current mode.
【学位授予单位】：北京协和医学院
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R816.5

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